I'm just wondering about something here.
What types of Safety controls and systems do you guys encounter in factories, using large manually-operated and semi-automatic machinery, in the US?.
How prevalent is the use of Light Curtains and Machine Guards, where you work?
Have you ever encountered a place where someone has over-ridden the safety controls?.

Trumpy-
We have evertyhing you can think of for a guard here. OSHA rules require protecting operators. We also have some very clever operators who insist on defeating every know safety device in some way. Generally they get offended when they get turned in for a violation too.

Light curtains are the best, short of jumper wires (seen it) they are the hardest to defeat.

mvpmaintman,
Thanks for the reply, mate!.
How far does PLC control over machinery in the US go?.
How would a machine controlled by a PLC be made to "fail safe" under a fault in the wiring or a supply failure?.
I've heard of instances where PLC controlled machines have just kept going with the controls all wired back to front here, is this the case in the US?.

What I was looking for here was, how can we make Industrial Machine's safer and more "user friendly".

Trumpy on the PLC equipment I deal with, the Emergency stop button is hardwired to the MCR. We are not allowed to use an Estop in the PLC. We also use light curtains, step mats (shut the machine off if the operator steps into a hazard area), safety gates & cables (both interlocked into the Estop line). I don't think we will ever get them "idiot proof", the idiots just keep getting smarter!

spkjpr,
This is what I mean,
You can never programme a PLC to take into account, any idiot that is going to try and defeat the system.
Normally, we would input any Estop or safety device as a Normally Closed contact, that way, if a wire breaks, or similar such thing, the system stops.
Thanks for your input, bud!.

Trumpy:

In our company, we use all manner of "safety" equipment, most having been listed before. These include: Safety E-stops, light curtains, photohelics, safety cables, physical barriers, emergency pendant switching (which moves all controls to the pendant, disabling all other controls during an emergency) and pressure sensitive mats.

All have their high points and lows, and each can be defeated in different ways depending on who attempts the defeating.

What exactly do you want to know???

Hazmat,
I was just wondering what types of Safety Controls were used in the US in Industrial sites.
I never really set out with a single goal in mind for this topic.

What I was looking for here was, how can we make Industrial Machine's safer and more "user friendly"....

EDUCATE the worker that the guards are there for his/her safety and that the output of the machine is NOT the most important thing about operating that machine. Rather, they being there runing the machine day-in-and-day-out in safe and productive manner.

Until we speak this and walk this line, employees will ALWAYS attempt to defeat the very features we have spent $$$ to protect them!

Bryan,
Darn good point, mate!.
You really have to look behind the reason WHY the said safety systems are being defeated in the first place.
Is it because they are time consuming to operate or don't work correctly, or have they not been installed correctly.
The number of times I've seen an incorrectly installed Limit switch or Proxy switch.
Also, how often are these safety devices tested?.
One question, how prevalent is the Pull-Wire on an Industrial site in the US, where a horizontal wire is stretched from one end of the process to the other, a vertical pull on this wire will shut-down all Electrical and Pneumatics gear?.

We have almost everything that has been said. Also something i see alot in the japanesse factories i have worked in is that they love to build cages around the entire mach except were the operator works. we use alot of door saftey switchs and limits. In my 10yrs of maint experience i would say one of the biggest reasons people by pass its the time factor they get tired of waitting. This problem usually could be solved if the engineer who decided to put the saftey componet in would listen to the maint guy and the operator a little more often. As for the pull cords we have them on our paint line and assembly lines

Trumpy, sorry I haven't been back, 7 days a week at work. I agree with jlh about switches being bypassed is to save time. We have 5 manufacturing lines that use a pull cord E-stop. We test aour E-stop devices when the machine is PM'd. The co. I work for just recently posted that if anyone is caught not wearing PPE or defeating safety devices they can be dismissed.

spkjpr,
No worries, mate!,
Good to see you're still getting time to post here, you're more than welcome.
I wouldn't hesitate to dismiss a person that was found to be tampering with E-stops and the like, after all we don't put these things in for the sheer fun of it!.
What would happen if some guy lost a limb because the guy on the shift before disabled the E-stop?.

Hey Trumpy, I just investigated a workplace accident where the employee was actually injured when he got into the electrical panel to shut off the power to the light curtains and alarms on a line. Not only is it a GREAT case why unqulaified personnel should not be opening electrical panels they know nothing about, it is a prime example of the lengths that employees will go to, to defeat the very mechanics in place to protect their futures. The employee was fired and the Union is taking his termination to arbitration. Not slamming unions here, but here is a guy that put an additional 40+ workers at risk should he have been sucessful in shutting down the systems and the very union that he put at risk is fighting for him!!!! I am sorry but this is one that they should just let go.

SAFETENG,
Well,
This certainly heralds a new era in stupidity.
I've never liked the idea of Un-Authorised Personnel, having access to Circuit-Breakers, Fuses or any other equipment that is installed for the protection of Life and Property.
Also, I'd agree, that the Union, should leave this one alone.
To represent a worker that has done a thing like this, sounds rather strange.